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Portable Mobile Solar Chargers - The Facts

Posted by
Randy Gray
on January 05, 2017

The market for portable solar modules and chargers is
growing with multiple brands entering the market.The mobile solar market is growing in tandem
with the impressive growth in the mobile handheld device market and the
wearable markets.

In the past, portable solar chargers were considered a
"green" product emulating a "green" lifestyle.While this can still be somewhat true, the
portable solar products are now being tailored for the outdoors enthusiast,
outdoor professionals, and in military applications.The purpose is more focused on performance
and convenience for the mobile lifestyle (not just "green").

The cost of the solar panels have decreased, along with the
standard crystalline panels used on residential and industrial solar arrays.
The standard residential panels have reached commodity levels when considering availability
and pricing.

"You get what
you pay for"

Price has always been
a factor when considering a solar product.In residential solar, the common metric is the final cost per watt of
electricity provided for the home.The
solar panels themselves are rated and marketed on a cost-per-watt price point.

Portable solar chargers are slightly different. If the
manufacturing steps are the same, the smaller panels carry a higher cost per
watt due to the decreased output from the smaller surface area of the panel.
The value lies in the portability, convenience, and necessity (Compare a
desktop to a laptop computer; pay a premium for the portability).

The standard residential panels adhere to industry standards
in manufacturing and testing and are often tested by third parties.So you can be reasonably sure that a
reputable manufacturer will meet industry standards and be of decent quality.

The smaller mobile solar charger market has not followed the
same path.These products are not held
to any industry standard and usually not tested by any third party.Many brands are far over-stating the power
output of their solar charging products.These panels could be of questionable quality and durability, so a low
cost folding solar charger could perform under the marketed specs and not
withstand the hands-on often rugged treatment of a portable, outdoor product.

Look for a company that has tested their products and share
their results.Look for actual
durability testing, long-term tests, and output performance testing.I have personally used some inexpensive solar
garden lights that didn't last the summer. The coating on the panels were not
UV protective and clouded up after exposure to the sun.

The old saying, "you get what you pay for",
definitely applies to the portable solar market.

What are Thinfilm and
flexible panels?

Thinfilm and flexible have become broad terms that are not
well defined in the solar industry.These days, thinfilm is not a technical term and more of a marketing
term.Some companies are turning to
other terms like "rollable", "paper-thin" or "solar
paper" to differentiate their products from others.Flexible is another term that is loosely
defined.The problem is, how flexible is
it?Is it semi-flexible or semi-rigid,
how much can it flex, can you roll it, what radius can it bend before breaking
or other damage would occur?

So be aware that the terms "thinfilm" and "flexible"
can apply towards different solar cell technologies and the properties can vary
widely.Look for a thinfilm panel that
can flex the amount you need and on a substrate that is still durable.

Compare CIGS
flexible, to silicon crystalline panels

Standard silicon crystalline technology has been around for
a long, long, time.With modern
manufacturing techniques and the basic laws of supply and demand, these solar
panels are now low cost and the resulting energy cost is almost on par with
fossil fuel generated electricity.

Copper Indium Gallium Selenide (CIGS) technology does not
use silicon and can be applied to flexible substrates instead of glass. The
manufacturing methods are not as efficient and cost effective resulting in a
higher cost per watt. Arguably, more effort could be focused on the manufacturing
techniques and efficiencies and bring the cost of CIGS panels down to more acceptable
levels.

The real advantage of CIGS is the light-weight, flexible
solar modules that open the door for non-standard designs and
applications.This includes Building
Integrated Photovoltaics (BIPV) and on mobile devices with limited flat areas
and flexing surfaces.The resulting
products typically have a lighter weight and no worries of breaking or cracking
glass, with an expected lifetime of 15 to 20 years on well designed products.

Light-weight - Will you be carrying the charger around with
you? If so, are you hiking or camping where weight or payload is a factor.

Size - Again, will you be carrying the charger around with
you? Consider a small charger or a folding charger that can fold up for compact
size and/or fold out for more charging power.

Flexible - Will the solar charger be exposed to conditions
that could damage or crack a glass panel? Sometime rough handling can damage a
solar panel, so a flexible panel could reduce any damage and even absorb some
of the shock.

Enough Power - What are you trying to charge? How many
devices do you want to charge? Check the specifications on the device you are
trying to charge.A laptop will
typically require more power than a cell phone or a couple of rechargeable AA
batteries.

Quality - How long will the solar charger last? Be sure the
solar charger meets the marketed specifications for power output. Also be sure
the final product is manufactured well and carries a decent warranty.

Price - Price is always a factor and there are multiple
ways to compare or rate solar chargers.Whether you are comparing a cost-per-watt, or features on the charger,
rugged qualities, type of solar, etc... Be sure to compare the facts, not the
hype.